1 /* e_sinhf.c -- float version of e_sinh.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16 #ifndef lint
17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_sinhf.c,v 1.8 2005/11/13 00:41:46 bde Exp $";
18 #endif
19
20 #include "math.h"
21 #include "math_private.h"
22
23 static const float one = 1.0, shuge = 1.0e37;
24
25 float
__ieee754_sinhf(float x)26 __ieee754_sinhf(float x)
27 {
28 float t,w,h;
29 int32_t ix,jx;
30
31 GET_FLOAT_WORD(jx,x);
32 ix = jx&0x7fffffff;
33
34 /* x is INF or NaN */
35 if(ix>=0x7f800000) return x+x;
36
37 h = 0.5;
38 if (jx<0) h = -h;
39 /* |x| in [0,9], return sign(x)*0.5*(E+E/(E+1))) */
40 if (ix < 0x41100000) { /* |x|<9 */
41 if (ix<0x39800000) /* |x|<2**-12 */
42 if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
43 t = expm1f(fabsf(x));
44 if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one));
45 return h*(t+t/(t+one));
46 }
47
48 /* |x| in [9, logf(maxfloat)] return 0.5*exp(|x|) */
49 if (ix < 0x42b17217) return h*__ieee754_expf(fabsf(x));
50
51 /* |x| in [logf(maxfloat), overflowthresold] */
52 if (ix<=0x42b2d4fc) {
53 w = __ieee754_expf((float)0.5*fabsf(x));
54 t = h*w;
55 return t*w;
56 }
57
58 /* |x| > overflowthresold, sinh(x) overflow */
59 return x*shuge;
60 }
61